Is This Proof Correct? Ask & Discuss Here

  • Context: Graduate 
  • Thread starter Thread starter JasMath33
  • Start date Start date
  • Tags Tags
    Calculus Proof
Click For Summary

Discussion Overview

The discussion revolves around the correctness of a proof related to Lipschitz continuity presented in a book. Participants are examining the clarity and completeness of the proof, particularly focusing on the ending and whether it adequately conveys the conclusion that a function is Lipschitz continuous.

Discussion Character

  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant expresses doubt about the proof's correctness, specifically regarding its ending, which does not explicitly state that the function is Lipschitz.
  • Multiple participants respond that the proof appears correct and question the basis for the initial doubt.
  • One participant suggests that the expectation for a concluding statement about Lipschitz continuity may stem from a lack of familiarity with the concept.
  • Another participant draws an analogy to the definition of even numbers to illustrate that certain conclusions may be implicitly understood in mathematical contexts.
  • There is a suggestion that using a different constant in the proof might have made the conclusion more apparent.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the correctness of the proof. While some find it acceptable, others express uncertainty about its completeness, indicating a lack of agreement on the matter.

Contextual Notes

The discussion highlights potential assumptions about familiarity with Lipschitz continuity and the expectations for mathematical proofs, which may not be universally shared among participants.

JasMath33
Messages
21
Reaction score
1
I was reading this book yesterday and looking at this proof/justification. I was thinking it is possibly incorrect, but wanted to get some other opinions. Here is the example they gave in the book with the work attached.

upload_2016-7-6_8-50-23.png


upload_2016-7-6_8-50-53.png
 
Physics news on Phys.org
Looks ok to me. What does make you think it might be incorrect?
 
fresh_42 said:
Looks ok to me. What does make you think it might be incorrect?
I guess what threw me off was the ending. I was just expecting to see something stating therefore the the function is Lipschitz. I guess in the book, they wanted you to just in your head think that.
 
JasMath33 said:
I guess what threw me off was the ending. I was just expecting to see something stating therefore the the function is Lipschitz. I guess in the book, they wanted you to just in your head think that.
Well, it's the definition of Lipschitz continuity. If one has to show a number ##n## is even and shows it is divisible by ##2##, nobody would complain about a missing "... therefore ##n## is even", because we are used to the concept of even numbers. It is the same here: simply a matter of acquaintance. Maybe it would be a little more obvious if one had chosen ##L## instead of ##M## as the constant.
 
fresh_42 said:
Well, it's the definition of Lipschitz continuity. If one has to show a number ##n## is even and shows it is divisible by ##2##, nobody would complain about a missing "... therefore ##n## is even", because we are used to the concept of even numbers. It is the same here: simply a matter of acquaintance. Maybe it would be a little more obvious if one had chosen ##L## instead of ##M## as the constant.
Yeah I see what you are saying now. It makes sense. Thanks.
 

Similar threads

  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 20 ·
Replies
20
Views
2K
  • · Replies 17 ·
Replies
17
Views
11K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 8 ·
Replies
8
Views
3K